Text sicher...

/**
 * clean_text
 *
 * diese function wandelt alle Sonderzeichen eines textes die falsch
 * interpretiert werden koennen und die hltml tags um.
 * also wenn man einen text von einer texbox oder input in eine DB
 * abspeichern will.
 * dann steht der text sauber in der DB drinn.
 * ohne das falsche Formatierungen dabei heraus kommen.
 *
 * @return formatet string, special chars are fomrated into &#
 * @param text as string $text
 * @desc replaces all special chares into html entities
 * @author banana mail@bananas-playground.net
*/
function clean_text($text)
{
    if($text == "")
    {
        return "";
    }
    else
    {
    	$text = trim($text);
		$text = stripslashes($text);
 
		// prevents adding everytime you change text a new <br />
		$text = preg_replace("/<br \/>/","",$text);
		//Remove sneaky spaces
		$text = str_replace( chr(0xCA),"",$text );
		$text = str_replace( "&","&",$text );
		$text = str_replace( "<!--","&#60;&#33;--",$text );
		$text = str_replace( "-->","--&#62;",$text );
		$text = preg_replace( "/<script/i","&#60;script",$text );
		$text = htmlentities($text);
		$text = str_replace( ">",">",$text );
		$text = str_replace( "<","<",$text );
		$text = str_replace( "\"",""",$text );
		// Convert literal newlines
		$text = preg_replace( "/\n/","<br />",$text );
		$text = preg_replace( "/\\\$/","$",$text );
		$text = str_replace( "!","!",$text );
		// IMPORTANT: It helps to increase sql query safety.
		$text = str_replace( "'","'",$text );
		$text = preg_replace("/&#([0-9]+);/s", "&#\\1;", $text);
 
        return $text;
    }
}